Variable distance doppler generator

ABSTRACT

A plurality of acoustic pulsato units are mounted in a vertical stack with the axes of the pulsato rotors horizontal in spaced parallel array. Reflector walls on opposite sides not only direct the sound frontally but also serve as the primary means for producing frequency deviations by Doppler effect since the distance between the reflector walls and the mouths of the sound channels changes in accordance with the angular movement of the rotors. Pulsato sound at a high energy level is efficiently radiated.

United States Patent Sharp VARIABLE DISTANCE DOPPLER GENERATOR [72]Inventor: Paul H. Sharp, Sierra Madre, Calif.

[73] Assignee: Columbia Broadcasting System, Inc.,

New York, N.Y.

[22] Filed: May 26,1971

[21] Appl.No.: 147,022

[52] US. Cl. ..181/31 B, 181/27 A [51] Int. Cl ..G10k 13/00, l-lO4r 1/28[58] Field of Search...18l/27 A, 31 B, 31 R; 179/1 J;

[5 6] References Cited UNITED STATES PATENTS 3,057,430 10/1962 Santi..181/27 A [451 Oct. 3, 1972 3,070,660 12/1962 lppolito ..l8l/27A3,315,760 4/1967 Schwendener ..181/31 B 3,495,022 2/1970 Koehl ..84/1.25

Primary Examiner-Stephen J. Tomsky Attorney-Flam and Flam 5 7] ABSTRACTA plurality of acoustic pulsato units are mounted in a vertical stackwith the axes of the pulsato rotors horizontal in spaced parallel array.Reflector walls on opposite sides not only direct the sound frontallybut also serve as the primary means for producing frequency deviationsby Doppler effect since the distance. between the reflector walls andthe mouths of the sound channels changes in accordance with the angularmovement of the rotors. Pulsato sound at a high energy level isefficiently radiated.

9 Claims, 9 Drawing Figures PATENTED 0m 3 I972 SHEH 1 OF 3 w a A mp w VZ A N vp 5 J w W] M 0 T W, H M 9 WW 2. m A Z w J m W w PATENTEDUU 3 I972SHEET 2 OF 3 INYENTOQ P001. H. S amp flrroe/vs s 5 1 VARIABLE DISTANCEDOPPLER, GENERATOR BACKGROUND OF THE INVENTION 1 Field of Invention Thisinvention relates to speaker systems, and particularly to high powerspeaker systems incorporating acoustic pulsato apparatus.

2. Discussion of the Prior Art Many acoustic instruments such astrumpets and trombones are capable of producing extremely loud sounds.An electronic instrument such as an organ or electric guitar played inconcert with an acoustic instrument suchas a trumpet, requires a highlevel of amplification. High powers have been achieved by driving aplurality of speakers from a common high power amplifier. As many as tenspeakers may be more or less compactly mounted in a common cabinet.

Performers insist upon using acoustic pulsato apparatus. Such apparatusis not so compact. Thus each speaker must have an associated rotarysound channel.

' Such rotary sound channels are not efficient in terms of OBJECTS OFTHE INVENTION Theprimary object of the present invention is to provide'arelatively compact pulsato speaker capable of efficiently producing highsound levels.

BRIEF SUMMARY OF THE INVENTION In order to achieve the foregoingobjective, I provide a reflector. Whereas a conventional reflectorproduces a beam from a fixed localized source, the present reflectorproduces a beam from a moving source with the distance between thereflector wall and the source changing so that a cyclic Doppler orpulsato effect is thereby created. The reflector thus performs a uniquecombined function of channelling sound energy as well as producing afull vibrant pulsato effect.

The reflector in one form of the invention comprises two wing plates atopposite sides of a speaker mounting panel, the plates being angled atabout 45. The pulsato rotors are mounted in front of the common mountingpanel there being a stationary speaker for each rotor mounted in back ofthe panel. In another form of the invention a plurality of pulsato drumsare coaxially stacked along the axis of the reflector. Each drum in thisinstance carries a speaker for rotation therewith. In both forms, notonly is acoustic efficiency maximized, but the pulsato effect is greatlyenhanced.

BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of theinvention will be made with reference to the accompanying drawings.These drawings, unless described as diagrammatic or unless otherwiseindicated, are to scale.

FIG. 1 is a pictorial view of a speaker system incorporating the presentinvention.

FIG. 2 is an enlarged transverse sectional view taken along a planecorresponding to line 2-2 of FIG. 1.

FIG. 3 is a vertical sectional view taken along a plane corresponding toline 3-3 of FIG. 2.

FIG. 4 is a fragmentary front elevational view of the speaker systemshoiving the stack of rotors.

FIG. 5 is a further enlarged fragmentary sectional view taken along aplane corresponding to line 5-5 of FIG. 2.

FIG. 6 is an isometric view of a modified form of the present invention.

FIG. 7 is a top plan view of the speaker system of FIG. 6.

FIG. 8 is a frontelevational view thereof with part of the cabinetstructure being broken away and shown in section.

FIG. 9 is a sectional view taken along a plane corresponding to line 9-9of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The following detaileddescription is of the best presently contemplated modes of carrying outthe invention. This description is not to be taken in a limiting sensebut is made merely for the purpose of illustrating the generalprinciples of the invention since the scope of the invention is bestdefined by the appended claims. Structural and operationalcharacteristics attributed to forms of the invention first describedshall also be at tributed to forms later described unless suchcharacteristics are obviously inapplicable or unless specific exceptionis made.

Four speakers l0, l2, l4 and 16 are supported one above the other on theback of a mounting panel 18. The panel 18 is enclosed within a cabinetwhich comprises the top wall 20, a bottom wall 22, and side walls 24 and26 (see also FIG. 2) and a rear wall 28. The speaker mounting panel 18is recessed within the frontal opening of the cabinet structure with itstop and bottom edges respectively abutting the inner surfaces of the topand bottom walls 20 and 22.

An enclosure for the speakers is completed by a pair of reflector panelsor walls 30 and 32. One reflector wall 30, for example (FIG. 2) extendsinwardly from the front vertical side edge of the cabinet opening at anangle of approximately 45 to the corresponding side of the speakermounting panel 18. The other reflector wall 32 similarly extends fromthe vertical side edge of the cabinet opening to the corresponding sideof the panel 18. The sound is accordingly beamed frontally to maximizeacoustic efficiency.

The speakers may all be driven by the electrical output of a musicalinstrument such as an electric organ, electric guitar, or the like.Amplifiers may conveniently be housed in the bottom of the enclosurebehind the reflectors 30 and 32.

The axes a, b, c and d of the speakers 10, 12, 14 and 16 are horizontaland vertically spaced one above the other, the speakers facing frontallyof the cabinet opening. In order to conduct the sounds outwardly, fouropenings are provided in the panel 18, one of which 34 is shown in FIG.5. Each opening is a composite, comprising a plurality of smalleropenings. The smaller openings together form a circular array providinga spider supporting a central hub 36. The speaker 10 is mounted upon aU-shaped bracket 38 attached to the panel 18 behind the opening 34. Acylindrical section 39 attached to the inside of the bracket 38 channelsthe sound from the speaker 10 to the region adjacent to compositeopening 34.

The sounds passing through the opening 34 are acted upon by a pulsatorotor 40 mounted in front of the speaker panel 18. The pulsato rotor 40in this instance is of a type shown and described in Schwendener U.S.Pat. No. 3,3l5,760 issued Apr. 25, 1967, and entitled ACOUSTIC DAMPINGDRIVE FOR PULSATO R TOR.

The pulsato rotor 40 is mounted coaxially of the corresponding speaker10. For this purpose a pair of bearings are provided for opposite endsof the rotor, one of the'bearings (not shown) being mounted upon aU-shaped bracket 42 (FIG. I) that straddles the rotor.

and the other of the bearings 43 (FIG. 5) being mounted at the hub 36 ofthe composite opening 34. A shaft 44 mounted by the bearings in turnmounts the pulsato rotor 40. In order to impart rotary movement to therotor, a pulley 46 is carried upon an inward extension of the shaft 34.A motor 48 (FIG. 2) on the inside of the panel 18 drives the pulley 46through a belt 50.

In order to produce characteristic vibrato and tremolo, the rotor 40rotates the sound pattern in such manner that the sound-pattern isrepeated at the rate of 5 to 8 cycles per second. For this purpose, therotor 40 channels the sound to an opening that moves orbitally.

The pulsato rotor 40 thus has a channel with throat region 52 (FIG. 5)at the rotor side registering with the panel opening 34. The channel hasa lateral mouth 54 (see also FIGS. 1, 2 and 4) that describes a circularorbit.

Similar pulsato rotors 56, 58 and 60 are provided for the other threespeakers l2, l4 and 16. Each pulsato rotor is provided with its ownmotor drive located on the inside of the panel. The rotors need not besynchronized.

The orbits of the rotor openings are described about horizontal axes.Unless the listener is located well off center relative to the rotoraxes, very little Doppler effect can be expected since the distancebetween the listener and the mouths of the channels changes onlyslightly during rotation. It is for this reason that a pulsato rotor isnormally mounted for rotation about a horizontal axis whereby thedistance between the mouth of the sound channel and the listener changescyclically by an amount corresponding to the diameter of the rotor.However, the simple panel mounting of the speakers and rotors is highlydesirable. A good common rear baffle is provided; the units areaccessible for repair.

The side reflectors panels 32 and 34 cooperate with the pulsato rotorsto produce a substantial distance deviation even for a listener situateddirectly in front of the cabinet. Thus, the distance between the mouth54 and either one of the reflector panels changes cyclically byfanamount corresponding to the diameter of the pulsato rotor. Accordinglyfull rich pulsato effect is restored even though the rotors themselvesare compactly oriented and mounted in a simple manner.

DETAILED DESCRIPTION OF MODIFIED EMBODIMENT In the form of the inventionillustrated in FIG. 6 through 9, a plurality of pulsato drums 80, 82, 84and 86 are mounted for rotation about a common vertical axis by the aidof a shaft 88. Inside each drum is a speaker that provides a radiallyoutwardly opening sound channelfThe'shaft 88 is rotated by a motor 90,pulleys 92, 94 and a flexible belt 96 all housed beneath a horizontalpartition 98 in a cabinet structure 100.

The cabinet structure includes a reflector 102 having a simple generallyparabolic curvature. Like panels 30 and 32 of the previous form, thecurved reflector 102 not only beams the sound for maximum efficiency butit also cooperates with the speaker channels to enhance the pulsatoeffect by virtue of the fact that the distance between the reflector 102and the opening of the sound channel is cyclically changing. The soundintensity is maximized for a given unit of power.

Intending to claim all novel, useful and unobvious features shown ordescribed, I make the following claims:

1. In a speaker system for acoustic pulsato apparatus:

a. a speaker cabinet having a frontal opening, said speaker cabinethaving reflector means at the op posite sides of said opening that areangled with respect to each other for beaming sound waves to anaudience;

b. a sound channel rotatable about an axis and having a sound emittingopening spaced from said axis to describe an orbit;

c. meansmounting said sound channel within the reflector means so thatsaid sound emitting opening moves toward and away from said reflectormeans upon rotation of said channel to produce a Doppler effect thereby;

d. motor means for rotating said sound channel at a rate to repeat thesound radiation pattern at a desired rate; and

e. means for acoustically driving said sound channel.

2. In a speaker system for acoustic pulsato apparatus:

a. a speaker cabinet having a frontal opening, said speaker cabinethaving reflector means at the opposite sides of said opening that areangled with respect to each other for beaming sound waves to anaudience;

b. means forming a plurality of individual sound channels each rotatableabout an axis and each having a sound emitting opening spaced from itsaxis to describe an orbit;

c. means mounting said sound channel means in adjacentrelationship-within the reflector means so that said sound emittingopenings move toward and away from said reflector means upon rotation ofsaid channels to produce Doppler effects thereby;

d. motor means for rotating said sound channel i means to repeat thesound radiation patterns of each at a desired rate; and

e. means for acoustically driving said sound channels.

3. The speaker system as set forth in claim 2 in which said soundchannels are formed by speaker cones carried on drums stacked togetherfor rotation about a common axis located parallel to and adjacent afocus of the reflector means.

4. The speaker system as set forth in claim 2 in which said soundchannels are formed by rotors mounted in front of a panel with the axesof the rotors spaced from each other and directed frontally of saidspeaker cabinet; said driving means being a plurality of speakersmounted behind the panel.

5. The combination as set forth in claim 4 in which said reflector meanscomprises a pair of angled wing panels adjoining the sides of saidspeaker mounting panel.

6. In a speaker system for acoustic pulsato apparatus:

a. a speaker cabinet having a front opening;

b. a speaker mounting panel recessed within the opening;

c. a plurality of speakers supported on the back of said mounting panel;a

d. side reflector panels angularly adjoining the speaker mounting panelfor beaming sound waves frontally of said cabinet;

e. a plurality of pulsato rotors rotatably supported on the front ofsaid mounting panel respectively in substantial coaxial alignment withsaid speakers, said rotors each having sound openings facing radiallyoutwardly and laterally of said rotors toward said reflector panels:

f. motor means for rotating said pulsato rotors to repeat the soundradiation patterns produced by each at a desired rate whereby said soundopenings move toward and away from said reflectors by an amountcorresponding to the orbits of said sound openings.

7. The speaker system as set forth in claim 6 in which said cabinet hasa rear wall, said panels completing an enclosure for the speakers.

8. The speaker system as set forth in claim 6 in which said motor meansis located behind said panels.

9. The speaker system as set forth in claim 6 in which each rotor hasits own motor located behind the mounting panel.

1. In a speaker system for acoustic pulsato apparatus: a. a speakercabinet having a frontal opening, said speaker cabinet having reflectormeans at the opposite sides of said opening that are angled with respectto each other for beaming sound waves to an audience; b. a sound channelrotatable about an axis and having a sound emitting opening spaced fromsaid axis to describe an orbit; c. means mounting said sound channelwithin the reflector means so that said sound emitting opening movestoward and away from said reflector means upon rotation of said channelto produce a Doppler effect thereby; d. motor means for rotating saidsound channel at a rate to repeat the sound radiation pattern at adesired rate; and e. means for acoustically driving said sound channel.2. In a speaKer system for acoustic pulsato apparatus: a. a speakercabinet having a frontal opening, said speaker cabinet having reflectormeans at the opposite sides of said opening that are angled with respectto each other for beaming sound waves to an audience; b. means forming aplurality of individual sound channels each rotatable about an axis andeach having a sound emitting opening spaced from its axis to describe anorbit; c. means mounting said sound channel means in adjacentrelationship within the reflector means so that said sound emittingopenings move toward and away from said reflector means upon rotation ofsaid channels to produce Doppler effects thereby; d. motor means forrotating said sound channel means to repeat the sound radiation patternsof each at a desired rate; and e. means for acoustically driving saidsound channels.
 3. The speaker system as set forth in claim 2 in whichsaid sound channels are formed by speaker cones carried on drums stackedtogether for rotation about a common axis located parallel to andadjacent a focus of the reflector means.
 4. The speaker system as setforth in claim 2 in which said sound channels are formed by rotorsmounted in front of a panel with the axes of the rotors spaced from eachother and directed frontally of said speaker cabinet; said driving meansbeing a plurality of speakers mounted behind the panel.
 5. Thecombination as set forth in claim 4 in which said reflector meanscomprises a pair of angled wing panels adjoining the sides of saidspeaker mounting panel.
 6. In a speaker system for acoustic pulsatoapparatus: a. a speaker cabinet having a front opening; b. a speakermounting panel recessed within the opening; c. a plurality of speakerssupported on the back of said mounting panel; d. side reflector panelsangularly adjoining the speaker mounting panel for beaming sound wavesfrontally of said cabinet; e. a plurality of pulsato rotors rotatablysupported on the front of said mounting panel respectively insubstantial coaxial alignment with said speakers, said rotors eachhaving sound openings facing radially outwardly and laterally of saidrotors toward said reflector panels: f. motor means for rotating saidpulsato rotors to repeat the sound radiation patterns produced by eachat a desired rate whereby said sound openings move toward and away fromsaid reflectors by an amount corresponding to the orbits of said soundopenings.
 7. The speaker system as set forth in claim 6 in which saidcabinet has a rear wall, said panels completing an enclosure for thespeakers.
 8. The speaker system as set forth in claim 6 in which saidmotor means is located behind said panels.
 9. The speaker system as setforth in claim 6 in which each rotor has its own motor located behindthe mounting panel.